In testing within clinical laboratories to measure various chemical constituents of body fluids obtained from patients, such as whole blood, blood serum, blood plasma, and the like, automated clinical analyzers may reduce the number of trained technicians required to perform the analyses, improve accuracy of the testing, and reduce the cost per test.
Typically, an automated analyzer includes an automated sample fluid aspirating and dispensing system, which is adapted to aspirate a sample of body fluid from one sample container and dispense the body fluid sample into another reaction container (e.g., a cuvette). The sample body fluid aspirating and dispensing system typically includes a pipette (otherwise referred to as a “sample probe”) mounted on a moveable arm, to perform the aspiration and dispensing functions.
One or more chemical reagents, which are specific to the test to be performed, may be disposed into the reaction container, thereby mixing the body fluid sample with the chemical reagent. By examining the reaction products resulting from mixing the body fluid sample and the reagent(s), the automated analyzer may determine a concentration of a specific chemical constituent contained therein. Upon completion of the testing, the automated analyzer may store or print the results of the test.
During the aspiration operation, the moveable arm, which may be under the control of a robotic controller, may position the sample probe above the sample container, and descend the probe into the container until the probe is partially immersed in the body fluid sample in the container. A pump or other aspirating device is then activated to draw (aspirate) a portion of the body fluid sample from the sample container into the probe. The probe is then ascended (retracted) from the sample container such that the body fluid sample may be transferred to the reaction container for testing. During the ascending step, sometimes clotted fluid (a clot, such as a fibrin clot) may be pulled (carried out) of the sample fluid on the probe. These types of clots carried out by the probe may be quite sizeable. In some instances, the clot may fall from the probe, and this may possibly contaminate the analyzer, areas around the analyzer, and/or possibly affect the test results of the sample being tested (or even other samples). Accordingly, the inventors recognized there is a need for determining such occurrences of clot carryout during probe ascending, such that the aforementioned problems may be avoided.